I have a 388 small block and I was using the stock TBI unit and the stock injectors for a 5.7. It ran lean at low speed cruise, and was still kinda lean at high speeds. WOT thottle it would be at stochiometric, but I know at WOT its supposed to be a little rich. Now with upgrading to 454 injectors, cruising has perfect a/f ratio. At WOT it still will not go rich, only stays in stoch. I am using a A/F guage off the O2 sensor to get the info. Will having the O2 farther away from the engine skew the readings? My O2 is in the collector. It does go into closed loop.